3D touch

Abstract

An electronic device can include a housing and an interface component. The interface component can at least partially define an interface surface, and the interface component and the housing can define an internal volume. A force sensor assembly can be disposed in the internal volume to detect an amount of force applied to the interface surface. The force sensor assembly can include a pressure decay sensor and a gap distance sensor disposed opposite a surface of the interface component.

What is claimed is: 
     
       1. An electronic device, comprising:
 a housing; 
 an interface component at least partially defining an interface surface, the interface component and the housing defining an internal volume; and 
 a force sensor assembly disposed in the internal volume to detect an amount of force applied to the interface surface, the force sensor assembly comprising:
 a pressure decay sensor to detect an increase in a pressure of the internal volume and an exponential time constant of a rate of decay of the pressure; and 
 a gap distance sensor disposed opposite a surface of the interface component, the amount of force being detected by a weighted combination of a first signal from the pressure decay sensor and a second signal from the gap distance sensor; 
 wherein a weight of the first signal and a weight of the second signal are based at least partially on the exponential time constant. 
 
 
     
     
       2. The electronic device of  claim 1 , wherein:
 the surface of the interface component and a surface of the gap distance sensor define a gap; and 
 the gap distance sensor detects a change in a distance of the gap. 
 
     
     
       3. The electronic device of  claim 2 , wherein the gap distance sensor detects a change in a capacitance associated with the gap. 
     
     
       4. The electronic device of  claim 1 , wherein the interface component comprises a touch sensitive display. 
     
     
       5. The electronic device of  claim 1 , further comprising a seal between the interface component and the housing. 
     
     
       6. The electronic device of  claim 1 , further comprising an atmospheric pressure sensor. 
     
     
       7. The electronic device of  claim 1 , wherein the interface component comprises a touch sensing component. 
     
     
       8. The electronic device of  claim 1 , wherein the interface component comprises a display assembly. 
     
     
       9. An electronic device, comprising:
 a housing; 
 an interface component at least partially defining an interface surface, the interface component and the housing defining an internal volume; 
 a pressure decay sensor disposed in the internal volume to detect an amount of force applied to the interface surface; and 
 a secondary sensor disposed in the internal volume, the amount of force being detected by a weighted combination of a first signal from the pressure decay sensor and a second signal from the secondary sensor, a weight of the first signal and a weight of the second signal based at least partially on an exponential time constant of a rate of decay of the pressure detected by the pressure sensor. 
 
     
     
       10. The electronic device of  claim 9 , wherein the pressure decay sensor detects an increase in a pressure of the internal volume. 
     
     
       11. The electronic device of  claim 9 , wherein the detected amount of force is based at least partially on the detected exponential time constant. 
     
     
       12. The electronic device of  claim 9 , wherein the pressure decay sensor comprises a microelectromechanical pressure sensor. 
     
     
       13. The electronic device of  claim 9 , wherein:
 the secondary sensor comprises a gap distance sensor; and 
 an internal surface of the interface component and a surface of the gap distance sensor define a gap. 
 
     
     
       14. The electronic device of  claim 13 , wherein the gap distance sensor comprises a capacitive gap distance sensor. 
     
     
       15. A method for determining an amount of force applied to an interface component of an electronic device having an internal volume, comprising:
 detecting an increase in a pressure of the internal volume; 
 measuring a rate of decay of the pressure; 
 determining the amount of force based at least partially on the rate of decay; and 
 detecting a change in a property of the electronic device above a threshold with a secondary sensor, wherein:
 determining the amount of force comprises combining a first weighted value based on the rate of decay with a second weighted value based on the detected change in the property; and 
 a weight of the first weighted value and a weight of the second weighted value are based at least partially on the rate of decay. 
 
 
     
     
       16. The method of  claim 15 , wherein:
 detecting the increase in the pressure comprises detecting the increase in the pressure with a pressure decay sensor disposed in the internal volume; and 
 detecting the change in the property comprises detecting a change in a capacitance associated with a gap between a surface of the interface component and a gap distance sensor disposed in the internal volume. 
 
     
     
       17. The method of  claim 15 , wherein:
 determining the amount of force comprises comparing the measured rate of decay to a baseline rate of decay; and 
 the method further comprises calibrating the baseline rate of decay.